Patent GB-971522-A (GB)
Title: Improvements in or relating to apparatus for handling volatile liquids
Inventor: PREW LIONEL ROY
IPC: F04D9/00
Filed: 1962-07-24
Abstract: 971,522. Liquefaction and revaporization of gases. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. July 22, 1963 [July 24, 1962], No. 28438/62. Heading F4P. [Also in Division F1] An apparatus for discharging, charging or maintaining the condition of the charge in a receptacle 1 for a volatile liquid in which the temperature of the liquid is kept sufficiently low for the vapour pressure of the liquid not to exceed atmospheric pressure or about atmospheric pressure, comprises a separator 4, such as a cyclone separator, for separating liquid from gas, a riser 2 extending from the bottom of the receptacle 1 to the separator, compressor means 19, 20, a conduit 17 for connecting the suction side of the compressor means to the separator, an alternative conduit 21 for connecting the suction side of the compressor means to the top of the receptacle, a condenser 36 or 37 for liquefying part or all of the output of the compressor means, and pressure reduction means 39, 40 or 50, 51 for reducing the pressure of the liquid output of the condenser to produce liquid and gas under a pressure at or about that in the receptacle. The receptacle may be a reservoir in the ground, an underground cavern or a ship's tank. The volatile liquid may be liquefied methane, ethane, propane, butane, hydrogen, nitrogen or oxygen. During discharging of the receptacle 1 the liquid supplied to the separator 4 passes through a conduit 5 to a pump 7 and thence to a charge/ discharge conduit 9 either through a shut-off valve 8 or through a shut-off valve 11, a steam heated heater 12 and a shut-off valve 14. The gas in the separator 4 passes through the conduit 17, compressor means 19, 20 and conduit 33 to either of the two condensers 36, 37 and thence to the reducing means 39, 40 or 50, 51. Each reducing means comprises an expansion valve 39 or 50 and a chamber 40 or 51 from which gas is led to the conduit 21 for recirculation and liquid is led to the receptacle 1. The condenser 36 is water cooled whereas the condenser 37 is cooled by evaporating refrigerant in a coil 48 of a refrigeration plant 45-48. A conduit 57 conveys any gas not condensed in the condenser 37 to a condenser 54, the condensate from which is fed through a conduit 59 to the receptacle 1. During charging, the liquid is fed through the conduit 9, a valve 15, a conduit 61 and an expansion valve 62 to a chamber 63. From the chamber 63 gas passes through a conduit 65 to the condenser 37, and the condensate therefrom passes to a conduit 49 and mixes with liquid supplied thereto from the chamber 63 by a conduit 64. The liquid then passes to the expansion valve 50 and chamber 51. Alternatively, the receptacle 1 may be charged through the conduit 9, a control valve 16 and part of the riser 2; the valve 16, once opened, being controlled by the pressure within the receptacle. In order to maintain the charge at the appropriate temperature and pressure in the receptacle 1, gas from the latter is passed through the conduit 21 to the compressor means and thence to either of the two condensers 36, 37 and its associated expansion valve and chamber. Various examples are described in the Specification of discharging and charging liquefied propane and butane from and to the receptacle and of maintaining these liquefied gases at particular temperatures and pressures therein. Specification 869,080 is referred to.